Mill



Dec. 4 1923. 1,476,260

B. MCFEELV MILL Filed Jan. ,6, 1920 A 2 Sheets-Sheet 1 2a 2 29 Z 28 112b 2;

fi itflesses .1 Inventor J Dec. 4, 1923. 1,476,260

M.-B. MCFEELY MILL Filed Jan. 6, 1920 2 Sheets -Sheoat 2 InventoryMayna/"dB MZPeeZy Patented Dec. 4, 1923.

rrsn srarss MAYNARD B. MQFEELY, OF PHILADELPHIA, PENNSYLVANIA.

MILL.

Application filed January 6, 1920. Serial No. 349,762.

' Mills of which the followin isa s ecification.

Que object of my invention is to provide an improved mill which isparticularly adapted for grinding cereals into granular form and is ofthe type in which'the outlet end of the grinding casing is provided witha gate or other closure which is moved into an open position to permitthe ground material to pass out of the grinding casing; said gate orclosure being automatically re turned. In mills of this type previouslymade, spring pressure was exerted on the gate or closing means and inview of the fact that the discharge from the casing is not always even,improper grinding resu ted in view of the fact that the gate acteddifferently when various pressures were exerted upon the same due to thedischarge of the material. In other words, when masses of variousdensities were discharged, the character of the spring pressure was incapable of properly forming the outlet required and in view of this factthe d1scharged material often came through the machine in improper formfor commercial purposes.

Another object of my invention 1s to so construct the automatic movingmeans for the discharge gate that it will permit an even discharge andwill respond properly to various pressures exerted by differentdensities and quantities of material p ssing out of the mill therebypreventing the belching of lumps of material as fre-- quently occurredin old types of machines.

A further object is to make the device of my invention of a strong anddurable con struction. l

These objects, and other advantageous ends which will be describedhereinafter, l attain in the following manner, reference being had tothe accompanying drawings in which c Figure 1 is a longitudinalelevation of a mill constructed in accordance with my invention,

Figure 2 is an end elevation of Figure 1,

Figure 3 is a longitudinal sectional elevation taken on the line 3--3 ofFigure 2,

Figure 4 is an end view of a conical grinding shell made in accordancewith my invention,

Figure 5 is a developed sectional view taken on the line 55 of Figure4;,

Figure 6 is a fragmentary end view looking in the direction of the arrowat of Figure 5, and

Figure 7 is a fragmentary end elevation looking in the direction of thearrow g of Figure 5.

Referring to the drawings, 8 represents a base including a casing 9having a substantially cylindrical portion 10 and a conical grindingshell 11 in axial alignment with the cylindrical portion 10. A shaft 12extends through the casing 9 and is mounted in bearings 13 formed on anarm 1% of the base 8. A pulley 15 or other suitable means can be securedto the sha 't for the purpose of rotating the same. The inner surface ofthe conical grinding shell 11 is provided with a number of grooves 16which arearranged in the form of helical grooves extending from the wideto the small outlet end or opening 17. These grooves, as shown inFigures 5 to 7 inclusive are deeper at their forward ends and graduallybecome shallower until they reach the end providing the opening ordischarge port 17. In addition to being of varying depth, these groovesare of varying widths; being wider at the end of largest diameter of theshell 11 and becoming narrower adjacent the opposite end of said shell.The shaft 12 has secured thereon a screw conveyor 18 an rsiinged withinthe cylindrical portion 10 of the casing 9; said cylindrical portionhaving a hopper 19 into which the material to be ground is discharged.The portion of the shaft 2 which extends within the grinding shell 11has a helical grinder 20 having edge portions 21 which tapersubstantially in the direction of the inner surface of the grindingshell 11; said edges being placed in close proximity to said innersurface of the grinding shell; Thus the material during the rotation ofthe shaft 12 is moved by the conveyor 18 into engagement with thegrooved inner surface of the grinding shell 11 and the helical grinder12 causes said material to be forced against the grooved inner surfaceof the shell and at the same time move toward the discharge port oropening 17. This causes the grinding of the material and at the sametime the ground material is conveyed due to the character of the helicalgrinder 20 toward the opening 17. The fact that the grooves are ofvarying width and depth throughout their lengths as above describedcauses the material first to be broken or ground into comparativelylarge granular particles and then to be ground into smaller sizeparticles as they move toward the opening 17.

A bracket 22 is secured to the outer portion of the grinding shell 11and this bracket forms a bearing for a pivot pin The outer end of thebracket 22 is bifurcated at the portion through which the pivot pin 23extends and an arm 24 fits between the i urcations and is secured to thepivot pin 23. The upper end 25 of the arm 24 has a pin 26 extendingentirely therethrough; the opposite ends of said pin being preferablymovable within slots 27 in lugs 28 on a gate 29 so as to swingably mountthe gate upon the arm 24 by a movable connection. The lugs 28 are spacedapart and the arm 24 freely fits between said lugs. The forward end ofthe grinding shell 11 has guiding lugs 29 so as to form a slidingbearing for the gate 29 in alignment with the discharge port or opening17, out of which the ground material is adapted to pass.

An arm or rod 30 is secured to the pivot pin 23 outside of the bracket22; said rod actually forming a bell crank lever with the arm 24. Therod 30 extends toward the cylindrical portion 10 of the casing 9 andnormally occupies a substantially horizontal position. A weight 31 ismounted on the rod 30 and can be secured in various positions thereon bymeans of a set screw 32. Thus the weight 31 will operate through themedium of the 'rod 30 and arm 25: to normally hold the gate 29 in aposition to close the discharge opening 17.

I preferably connect the rod 30, adjacent its free end, by a coiledspring 33; said spring including a turn-buckle 34L which serves as atension regulating or varying device for said spring 33. As illustratedthe end of? the turn-buckle opposite the spring is connected to the base8 so that by turning said turn-buckle the tension ot the spring 33 canbe varied to exert more or less pull on the rod in someinstances,according to the character of the material being ground I may dispensewith the spring 33 and the turn buckle 34; in which case the weight 31will serve as automatic closing means for the gate 29.

By the above construction the weight 31 at all times acts upon the gate29 with substantially equal pressure and thus the resistance offered tothe material within the mill is substantially constant and insuresproper and even grinding and discharge.

By providing the lugs 29 as illustrated, the gate 29 will move outwardlyin the direction of its axis only. In other words by providing the lugs29 and having the pin and slot connection between the gate and the arm2%, the gate will not tilt during its opening movement but on thecontrary will move bodily'in the direction of the axis of the grindingshell. Thus the. amount of opening provided by the gate will be equalthroughout its circumference and equal portions of the dischargedmaterial will therefore be delivered throughout the entire circumferenceof the discharge opening; thereby compelling the mill to delivermaterial which is all similarly ground when passing out of the dischargeopening.

While I have described my invention as taking a particular i orm, itwill be understood that the various parts of my invention may be changedwithout departing from the spirit thereof, and hence I do not limitmyself to the precise construction'set forth, but consider that I am atliberty to make such changes and alterations as fairly come within thescope of the appended claims.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is l. A mill of the character describedcomprising agrinding shell having a discharge opening at one end;guiding lugs spaced apart around the portion of said shell providingsaid opening, said guiding lugs terminating in outer free ends extendingbeyond said opening; a member pivotally mounted to swing away from saidopening; a gate slidably mounted within the space precribed by saidlugs, and having a slidable connection with said member; and meansengaging said member and arranged to exert a yielding pressure thereonand on said door substantially as described. 7

2. A mill 01 the character described comprising a. grinding shell havinga discharge opening at one end; guiding lugs spaced apart around theportion 0t viding said opening, said guiding lugs terminating in outertree ends extend ing beyond said opening; a bell crank lever arrangementhaving its axis spaced from said opening and adapted to swing away fromsaid opening; a gate'slidably mounted withinthe space prescribed by saidlugs and having a loose connection with one leg of said bell crank leverarrangement; and means connected to the other leg of said bell cranklever arrangement adapted to exert a yielding pressure thereon fornormally urging said door to closed position, substantially asdescribed.

3. A mill of the character described including grinding shell having a,discharge opening, guiding lugs spaced apart around the portion of saidshell providing said opensaid shell proing, said guiding lugsterminating in outer free ends and extending beyond said opening; a gateslidably 'mounted Within the space prescribed by said lugs, said gatehaving slotted lugs projecting therefrom; a pivot pin spaced from saidopening; a freely adjustable arm secured to said pivot pin and having apin extending within the slots of the lugs on said gate; a rod securedto said pivot pin; and means for exerting a yielding pressure on saidrod, substantially as de scribed.

4. A mill of the character described including a grinding shell having adischarge opening; a gate; means for supporting and guiding said gatewhereby it can be moved toward and from said opening, said gate MAYNARDB. MCFEELY.

Witnesses:

AUGUSTUS B. COPPES, CHAS. E. POTTS.

